JP2000284589A - Developing device, developing cartridge, process cartridge and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contamination of the inside of an image forming device by a developer and to satisfactorily form a thin toner film on a developer support by disposing a lubricative layer on the surface of an elastic regulating member in the region from the contact nip part which comes in contact with the developer support by way of the developer to the front edge part of the regulating member. SOLUTION: A terminal lubricative layer 71 is disposed on the surface of an elastic blade 7 in the region from the contact nip part 7a which comes in contact with a developing sleeve by way of a toner on the surface of the sleeve to the front edge part 7b of the elastic blade 7. The terminal lubricative layer 71 is denoted by slanted lines and is provided in a non-developing region in the longitudinal direction. The terminal lubricative layer 71 comprises a material different from that of the elastic blade 7 and is bonded to the surface of the elastic blade 7. The toner is not captured or fused on the nip part near the edge part of the elastic blade and a toner layer is not formed in thick stripes at both ends of the contact nip part 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of electrophotography such as an electrophotographic copying machine and an electrophotographic printer, and particularly relates to an overall configuration of a phenomenon apparatus, a developing cartridge, a process cartridge and an image forming apparatus. .

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image formed on an image carrier is visualized as a toner image by a developing device.

As one of such developing devices, various dry type one-component developing devices have been proposed and put into practical use. However, it is difficult for any developing device to form a thin layer of toner, which is a one-component developer, on a developer carrier. However, at present, there is a demand for improvements in image resolution, sharpness, and the like, and development of a method and apparatus for forming a thin layer of toner is indispensable, and several measures have been proposed for this.

For example, in Japanese Patent Application Laid-Open No. 54-43038, an elastic blade as an elastic regulating member made of a material such as metal or rubber is brought into contact with a developing sleeve as a developing material carrier, and the elastic blade and the developing sleeve are brought into contact with each other. A thin layer of toner is formed on the developing sleeve by regulating the passage of the toner between the abutting portions, and a sufficient tribo (triboelectric charge) is imparted to the toner by friction at the abutting portion. Techniques are disclosed.

In this case, when the non-magnetic toner is regulated by the elastic blade, a toner supply member for supplying the toner onto the developing sleeve is required separately. this is,
This is because, in the case of a magnetic toner, the toner can be supplied onto the developing sleeve by the magnetic force of a magnet in the developing sleeve, but in the case of a non-magnetic toner, the toner cannot be supplied by the magnetic force.

Therefore, a developing device 50 as shown in FIG. 7 has been proposed. In this conventional developing device 50, a polyurethane foam, a sponge, which comes into contact with the developing sleeve 52 at a position upstream of the elastic blade 51 in the rotation direction of the developing sleeve 52 in a developing container 54 containing a non-magnetic toner 53 as a one-component developer. The toner 53 is supplied onto the developing sleeve 52 by providing an elastic roller 55 using a foamed body or a fur brush and rotating in the direction of arrow D.

The toner supplied on the developing sleeve 52
53 is sent to the contact portion between the elastic blade 51 and the developing sleeve 52 with the rotation of the developing sleeve 52 and is made thinner, and is used for developing the electrostatic latent image on the photoconductor 1. Then, the developing sleeve 52
The remaining toner 53 that is not consumed in the above development is an elastic roller.
The toner 55 is peeled off, and new toner 53 is supplied to the developing sleeve 52 by the elastic roller 55 as described above, and the above operation is repeated. In addition, it is not preferable that the elastic blade 51 is made of a thin metal plate in terms of abrasion of the developing sleeve 52, and it is necessary to use a rubber material such as urethane or silicon to obtain a good thin toner layer.

By adopting such a configuration, a thin layer of non-magnetic toner can be formed on the developing sleeve 52 satisfactorily. However, since a non-magnetic toner is used, a magnetic toner cannot be used because magnetic attraction cannot be used as compared with a magnetic developing device which can easily hold the toner on the developing sleeve surface 52 by the action of a magnetic field using a magnetic toner. This makes it difficult to prevent the toner 53 from leaking out of the developing device 50. That is, since the developing sleeve 52 does not have a holding force except for the toner that has come out of the pressure contact portion of the elastic blade 51 to the developing sleeve 52 and is sufficiently frictionally charged, the developing sleeve 52
The toner easily leaks from the lower portion or near the end of the image forming device, that is, so-called "toner leakage", which easily causes a problem of soiling the inside of the image forming apparatus with the toner.

For this reason, a flexible seal member 56 is provided in the lower part of the developing container 54 at the toner collecting portion which is lightly pressed against the developing sleeve 52 to allow the passage of undeveloped toner and to allow the undeveloped toner to pass therethrough. The toner 53 is prevented from leaking from the lower part of the developing container 54, and a separate end seal member 57 is provided near the end of the developing sleeve 52.

FIG. 8 is a view of the developing device 50 of FIG. 7 viewed from the direction of the photosensitive member 1. For convenience of explanation, the developing sleeve 52 is not shown, and the contact nip portion 51a of the elastic blade 51 with the developing sleeve 52 is formed. This is indicated by oblique lines.

As shown in FIG. 7, an end made of a fiber material such as wool felt, Teflon pile, or a foam material such as polyurethane foam or sponge rubber is provided in a gap between both ends of the developing sleeve 52 and an opening of the developing container 54. A part seal member 57 is provided to prevent leakage of toner from between both ends of the developing container 54 and the developing sleeve 52 in the longitudinal direction. Further, as shown in FIG. 8, both ends of the elastic blade 51 are connected to the developing sleeve 52.
And between the end seal member 57, that is, by pressing the elastic blade 51 from the back side of the developing sleeve 52 contact portion by the end seal member 57,
The leakage of the toner from both ends of the elastic blade 51 is prevented.

However, in this conventional configuration, in order to ensure the sealing performance, the end sealing member 57 is pressed at a pressure higher than a predetermined value.
Must be pressed against the developing sleeve 52. For this reason, the elastic blade 51 sandwiched between the developing sleeve 52 and the end seal member 57 is deformed along the peripheral surface of the developing sleeve 52 from the contact nip portion 51a of the both ends of the elastic blade 51 with the developing sleeve 52 to the tip end 51b. Would. As a result, the elastic blade
The inner sides in the longitudinal direction of the two ends 51 tend to rise, and the developer layer formed on the developing sleeve 52 in this portion becomes excessively large compared to other portions. For this reason, the charging of the toner 53 becomes insufficient, and when a voltage is applied as a developing bias to the developing sleeve 52 during the developing operation, the toner 53 transfers to the photoconductor 1 from both ends of the developing sleeve 52 as fog,
This causes a problem that the toner 53 is scattered.

In order to prevent the deformation of the elastic blade 51, even when the end sealing member 57 is adjacent to the side surface of the end of the elastic blade 51, the toner 53 in the vicinity of the wall surface of the developing container 54 is smaller than that in the longitudinal direction. Since the movement is poor and the surface of the developing sleeve 52 is strongly rubbed as a result, the elastic blade 51
A similar problem occurs because the toner layers at both ends are formed thick.

In view of this, a proposal has been made to provide oblique cuts at both ends of the elastic blade 51.

FIG. 9 shows an elastic blade cut at both ends.
A developing device with 58 is shown. That is, the distal end of the elastic blade 58 from the lowest point in the rotation direction of the developing sleeve 52 of the contact nip portion 58a of the elastic blade 58
The distance to 58b is continuously shortened to the side end in the vicinity of both ends in the longitudinal direction of the elastic blade 58, and at least the leading end 58b at the side end of the elastic blade 58 is in contact with the contact nip 58a.
It is formed to be inside.

Accordingly, the pressing force of the end sealing member 57 causes the inside of the elastic blade 58 at both ends in the longitudinal direction to float, and the developing layer formed on the developing sleeve 52 in this portion is excessively large compared to other portions. Contact nip 58
Since the width of “a” is small and the edge is likely to be in contact with the edge, the contact surface pressure per unit area is large, and while preventing “toner leakage” at both ends of the developing sleeve 52 and the elastic blade 58, the non-magnetic toner is Was successfully formed, and the electrostatic latent image on the photoreceptor 1 was successfully developed.

[0017]

However, in the case of the above-mentioned conventional developing device, the contact nip portions 58a at both ends of the elastic blade 58 have a larger pressure per unit area than the contact nip pressure at the center. Therefore, if the developing operation is repeated many times, the toner 53 is likely to be caught in the contact nip portion 58a near the end of the elastic blade 58. Further, the toner 53 sandwiched between the contact nip portions 58a may be fused to the surface of the elastic blade 58 in the process of repeating the development operation in many lines.

The elastic blades 58 are lifted at both ends of the contact nip portion 58a where the toner 53 is sandwiched or fused.
The toner layer is formed thick in a streak shape, and the electric adhesion (mirror) to the developing sleeve 52 is reduced. As a result, the toner 53 is transferred to the photoreceptor 1 as fog, the toner 53 is spilled from the surface of the developing sleeve 52 to the outside (referred to as toner dripping), or is scattered, thereby significantly contaminating the inside of the image forming apparatus. Invited.

Regarding the toner drop, the above-mentioned toner having a spherical shape and a smooth surface (shape factor SF-1 is 100 to 180, shape factor SF-2 is 100 to 1).
With a toner of 40), it was more noticeable.

The present invention has been made to solve the above-mentioned problems of the prior art.
At both ends in the longitudinal direction of the developer carrier, toner is reliably prevented from being transferred to the photoconductor as a fog at the time of development, and the toner is prevented from being scattered or dripping. It is an object of the present invention to provide a developing device, a developing cartridge, a process cartridge, and an image forming apparatus which can stably and favorably form a thin toner layer.

[0021]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a developing container for accommodating a developer, and a rotatable container extending to an opening of the developing container. A developer carrying member, an elastic regulating member that abuts on the developer carrying member via the developer, and an upstream side in the rotation direction of the developer carrying member with respect to a contact portion of the elastic regulating member with the developer carrying member. A rotatable elastic roller provided in contact with the end portion, and an end seal member provided in a gap between the longitudinal end portions of the developer carrier and the opening portion of the developing container.
A lubricating layer is provided on a surface of the elastic regulating member, from a contact nip portion which comes into contact with the developer carrying member via the developer to a distal end portion of the elastic regulating member, wherein the developer has an elastic regulating member. It is prevented from being pinched between both longitudinal ends or fused to the surface of the elastic regulating member.

According to the second aspect of the present invention, the lubricating layer is made of a fluororesin having excellent slipperiness, and the developer is sandwiched between the longitudinal ends of the elastic blade or the surface of the elastic blade is formed. To effectively prevent fusion.

According to the third aspect of the present invention, the lubricating layer is made of a solvent-soluble fluorocarbon resin which is excellent in slipperiness, excellent in adhesion to an elastic blade and excellent in flexibility, and excellent in slipperiness. It is more effective to prevent the developer from being caught between the longitudinal ends of the elastic blade and from being fused to the surface of the elastic blade.

According to a fourth aspect of the present invention, the elastic blade surface lubricating layer according to any one of the first to third aspects is provided in a non-development area in the longitudinal direction of the elastic blade. The thin toner layer on the developing sleeve can be formed stably and satisfactorily by the elastic blade without causing any adverse effect on the image due to the lubricating layer.

According to the fifth aspect of the present invention, the distance from the lowest point in the rotation direction of the developer carrying member of the contact nip portion of the elastic regulating member to the developer carrying member to the tip of the elastic regulating member is adjusted by the elastic regulating member. The length of the elastic regulating member is continuously shortened in the lateral direction in the vicinity of both ends in the longitudinal direction, and at least the distal end of the elastic regulating member at the side end is formed in the contact nip portion. Even if the inner side in the longitudinal direction tends to float, the width of the nip contact portion is small and the contact portion is slightly edge-contacting. Thus, a thin layer of non-magnetic toner can be formed satisfactorily, and an electrostatic latent image on a photoreceptor can be developed well.

According to a sixth aspect of the present invention, there is provided a cartridge having the developing device according to any one of the first to fifth aspects, wherein the cartridge is detachably mountable to an image forming apparatus main body. A developing cartridge having excellent properties can be obtained.

According to the seventh aspect of the present invention, there is provided an electrophotographic photoreceptor, and at least the first aspect as a process means.
The developing device according to any one of the above items 5 to 5, is integrally formed as a cartridge, and is detachably mountable to the main body of the image forming apparatus, whereby a process cartridge excellent in handleability is obtained.

Here, the process cartridge includes the electrophotographic photosensitive member and at least one of the processing means.

The process cartridge of the present invention includes an electrophotographic photosensitive member and at least one process means. In the present invention, the process cartridge includes at least a developing device as the process means. Therefore, the mode of the process cartridge is as follows: the electrophotographic photosensitive member and the developing device, the electrophotographic photosensitive member and the developing device and the charging device, the electrophotographic photosensitive member and the developing device and the cleaning device, or the electrophotographic photosensitive member and the charging device and the developing device. And the cleaning means are integrally formed as a cartridge so as to be detachable from the apparatus main body.

The process cartridge can be attached to and detached from the apparatus main body by the user himself. Therefore,
The maintenance of the apparatus main body can be performed by the user himself.

According to the present invention, an electrophotographic photosensitive member on which an electrostatic latent image is formed, and the first to fifth embodiments for developing the electrostatic latent image formed on the electrophotographic photosensitive member. And an image forming apparatus excellent in user-friendly handling.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing the overall configuration of an image forming apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view of a developing device.

First, the overall configuration of the image forming apparatus will be described. This image forming apparatus includes a photosensitive drum 1 as an electrophotographic photosensitive member on which an electrostatic latent image is formed, and an electrostatic latent image formed on the photosensitive drum. And a developing device 4 for developing the image.

The developing device 4 may be formed into a cartridge as a developing cartridge and may be detachable from the main body of the image forming apparatus, or may be formed into a cartridge integrally with the photosensitive drum 1 and be detachable from the main body of the image forming apparatus. Is also good.

The photosensitive drum 1 rotates in the direction of arrow A (clockwise in the figure), is uniformly charged by a charging device 2 for charging the photosensitive drum 1, and an electrostatic latent image is formed on the photosensitive drum 1. An electrostatic latent image is formed on the surface by the laser beam 3, which is an exposure unit for writing.

This electrostatic latent image is developed in the vicinity of the photosensitive drum 1 and is developed as a process cartridge or a developing cartridge by a developing device 4 which is detachable from the image forming apparatus, and is formed as a toner image as a developer. Be visualized. In the present embodiment, so-called reversal development for forming a toner image on an exposed portion is performed.

The visualized toner image on the photosensitive drum 1 is transferred by a transfer roller 9 to a recording sheet 13 as a recording medium, and the transfer residual toner remaining on the photosensitive drum 1 without being transferred is scraped by a cleaning blade 10. The photosensitive drum 1, which has been taken out and stored in the waste toner container 11 and cleaned, repeats the above-described operation to form an image.

Here, the definition of the process cartridge includes the photosensitive drum 1 and at least one of the processing means.

The process cartridge of this embodiment is
The apparatus includes a photosensitive drum 1 and at least a developing device 4 as process means. Accordingly, as the mode of the process cartridge, the photosensitive drum 1, the developing device 4, the photosensitive drum 1, the developing device 4, and the charging device 2, the photosensitive drum 1, the developing device 4, the cleaning blade 10, the cleaning means such as the waste toner container 11, etc. Alternatively, the photosensitive drum 1 and the charging device 2
, The developing device 4 and the cleaning means are integrally formed into a cartridge so that the cartridge can be attached to and detached from the image forming apparatus main body.

The process cartridge can be attached to and detached from the image forming apparatus main body by the user.
Therefore, the maintenance of the image forming apparatus main body can be performed by the user himself.

On the other hand, the recording paper 13 onto which the toner image has been transferred is subjected to a fixing process by the fixing device 12, discharged outside the device, and the printing operation is completed.

Next, the developing device 4 according to the present invention will be further described with reference to FIG.

That is, the developing device 4 includes a developing container 14 for storing the toner 8 as a developer,
A developing sleeve 5 as a rotatable developer carrier extending to an opening of the developing sleeve 5 and an elastic blade 7 as an elastic regulating member abutting on the developing sleeve 5 via a toner 8.
And a rotatable elastic roller 6 provided in contact with the nip portion 7a of the elastic blade 7 with the developing sleeve 5 on the upstream side in the rotation direction of the developing sleeve 5, and both ends in the longitudinal direction of the developing sleeve 7 And an end sealing member 19 provided in a gap between the developing container 14 and the opening.

As the toner 8 contained in the developing container 14, a non-magnetic toner as a one-component developer is used. The developing sleeve 5 is located at an opening extending in the longitudinal direction in the developing container 14 and is installed to face the photosensitive drum 1.
The upper electrostatic latent image is developed and visualized.

The developing sleeve 5 has a substantially right half circumferential surface shown in the drawing protruding into the developing container 14 at the opening, and a left substantially half circumferential surface exposed to the outside of the developing container 14 to be laterally provided. The surface exposed to the outside of the developing container 14 faces the photosensitive drum 1 located on the left side of the developing device 4 with a small interval.

The developing sleeve 5 is driven to rotate in the direction of arrow B (counterclockwise in the figure). The surface of the developing sleeve 5 is appropriately adjusted to increase the probability of rubbing with the toner 8 and to convey the toner 8 well. It has irregularities. As an example, a diameter of 16 mm
Glass beads (# 60) on the aluminum sleeve surface
0), the surface roughness Rz is about 3
μm, and the gap with the photosensitive drum 1 is 300 μm.
The photosensitive drum 1 is rotated at a peripheral speed of 80 mm / s which is slightly faster than the peripheral speed of the photosensitive drum 1 of 50 mm / s. In order to prevent toner leakage from both ends of the developing sleeve 5, end sealing members 19 are provided at the opening of the developing container to seal both ends of the developing sleeve 5.

The toner seal configuration at both ends in the longitudinal direction of the developing sleeve 5 including the end seal 19 according to the present invention will be described later in detail.

A rubber material such as urethane or silicon or a thin metal plate of SUS or phosphor bronze having spring elasticity is used as a base material at a position above the developing sleeve 5, and a rubber material is adhered to a contact surface side of the developing sleeve 5. An elastic blade 7 made of, for example, one of which has a developing container
14, the vicinity of the free end side tip portion 7 b is provided so as to be in surface contact with the outer peripheral surface of the developing sleeve 5. The contact direction is a so-called counter direction in which the leading end side with respect to the contact portion is located on the upstream side in the rotation direction of the developing sleeve 5.

In one embodiment, the elastic blade 7 has a thickness
A 1.0 mm plate-like urethane rubber is adhered to the blade supporting metal plate 15.
g / cm (measurement of the linear pressure was calculated by inserting three metal sheets having a known coefficient of friction into the abutting part and pulling out the center sheet with a spring only).

The configuration of the elastic blade 7 at both ends in the longitudinal direction in this embodiment will be described later in detail.

The elastic roller 6 includes the elastic blade 7
The abutting nip portion 7b with the surface of the developing sleeve 5 is abutted on the upstream side in the rotation direction of the developing sleeve 5 and is rotatably supported. As this structure, a foamed skeleton-like sponge structure or a fur brush structure in which fibers such as nylon and nylon are planted on a cored bar are used for supplying the toner 8 to the developing sleeve 5 and removing the undeveloped toner. Preferred from the point. As an example, an elastic roller 6 having a diameter of 12 mm and a polyurethane foam provided on a cored bar was used. The contact width of the elastic roller 6 to the developing sleeve 5 is 1 to 8 mm
It is preferable to provide a relative speed to the developing sleeve 5 at the contact portion thereof. For example, the contact width is set to 3 mm, and the peripheral speed of the elastic roller 6 is set to 50 mm / s (developing speed) during the developing operation. The relative speed with the sleeve 5 is 130mm /
The driving means (not shown) was rotated at a predetermined timing so as to satisfy s).

The toner 8 is a non-magnetic one-component developer. As described above, the transfer remaining toner remaining on the photosensitive drum 1 without transfer is excellent in transferability, and is cleaned by a cleaning means such as a blade or a brush. In this case, a toner having advantages such as high lubricity and less wear of the photosensitive drum 1 is used. The shape is preferably spherical and the surface is smooth. Specifically, as a shape factor, SF-1 is 100 to 180, and SF-2 is
Those which are 100-140 are preferred. SF-1 and SF-2 are:
Using a Hitachi FE-SEM (S-800), 100 toner images were randomly sampled, and the image information was introduced into an Nicole image analysis device (Luzex3) via an interface and analyzed. The value obtained by the calculation is defined.

SF-1 = (MXLNG) ² / AREA × π / 4 × 100

SF-2 = (PERI) ² / AREA × π / 5 × 100

(AREA: projected area of toner, MXLNG: absolute maximum length, PERI: circumference)

The shape factor SF-1 of the toner indicates a degree of sphere, and as it increases from 100, it gradually changes from spherical to irregular. SF-2 indicates the degree of unevenness. As the value increases from 100, the unevenness of the toner surface becomes more conspicuous.

As for the method of producing the toner, if it falls within the range of the shape factor described above, besides the production method by the so-called pulverization method, it is described in JP-A-36-10231 and JP-A-59-53856. A method of directly producing a toner using a suspension polymerization method, a dispersion polymerization method of directly producing a toner using an aqueous organic solvent in which a polymer soluble in a monomer is insoluble, or a water-soluble polar polymerization initiation It is possible to produce a toner using an emulsion polymerization method typified by a soap-free polymerization method in which a toner is produced by directly polymerizing in the presence of an agent.

In the present embodiment, the shape factor SF of the toner
-1 can be easily controlled to 100 to 180, SF-2 can be easily controlled to 100 to 140, and the particle size distribution can be relatively easily obtained under normal pressure or under pressure to obtain a fine particle toner having a particle size distribution of 4 to 8 μm. Styrene and n as monomers
-Butyl acrylate, a salicylic acid metal compound as a charge control agent, a saturated polyester as a polar resin, and a colorant were added to produce colored suspension particles having a weight average particle size of 7 µm. Then, 1.5 wt% of hydrophobic silica was externally added to the toner, thereby producing a negative toner 8 having excellent transferability as described above and having little abrasion during cleaning of the photosensitive drum 1.

In the developing device 4 as described above, during the developing operation, the toner 8 in the developing container 14 is sent in the direction of the elastic roller 6 with the rotation of the stirring member 16 in the direction of arrow C.

Next, the elastic roller 6 of this toner 8 is
The toner 8 carried on the elastic roller 6 at the contact portion between the developing sleeve 5 and the elastic roller 6 is rubbed with the developing sleeve 5 at the contact portion between the developing sleeve 5 and the elastic roller 6. Is subject to triboelectric charging
It adheres on the developing sleeve 5. Then, the developing sleeve 5
With the rotation in the direction of arrow B, the elastic blade 7 is fed under the pressure of the contact nip portion 7a, where it is subjected to an appropriate tribo (amount of triboelectric charge) and is formed on the developing sleeve 5 in a thin layer. The sheet is conveyed to a developing section which is a section facing the photosensitive drum 1.

In this developing section, a thin toner layer formed on the developing sleeve 5 is applied to an AC voltage (developing AC bias) in which a direct current applied between the developing sleeve 5 and the photosensitive drum 1 by the power source 18 is superimposed. The photosensitive drum 1
The upper electrostatic latent image is developed as a toner image. Undeveloped toner not consumed in the developing section is
Is collected from the lower part of the developing sleeve 5 with the rotation of.
A seal member 17 made of a resilient sheet is
Is provided to allow the late developing toner to pass into the developing container 14 and to prevent the toner 8 in the developing container 14 from leaking from the lower portion of the developing sleeve 5. The collected undeveloped toner on the developing sleeve 5 is peeled off from the surface of the developing sleeve 5 at the contact portion between the elastic roller 6 and the developing sleeve 5. Most of the stripped toner is conveyed along with the rotation of the elastic roller 6 and mixes with the toner 8 in the developing container 14 to disperse the charge of the toner 8. At the same time, the rotation of the elastic roller 6 causes the developing sleeve 5 to rotate.
A new toner is supplied above and the above operation is repeated.

Next, the toner seal structure at both ends in the longitudinal direction of the developing sleeve 5 according to the present invention will be described in detail.

FIG. 3 shows the developing device 4 shown in FIG. 2 as viewed from the photosensitive drum 1 direction. In FIG. 3, the developing sleeve 5 is not shown.

As shown in FIG. 2, an end seal member 19 made of a fiber material such as wool felt or Teflon pile or a foamed material such as polyurethane foam or sponge rubber is provided at the opening of the developing container 14. The space between both ends of the sleeve 5 and the developing container 14 is sealed. This end seal member
Reference numeral 19 denotes a structure in which a Teflon pile is provided on the surface of wool felt in this embodiment, and the Teflon pile surfaces having high slidability are brought into contact with the peripheral surfaces of both ends of the developing sleeve 5.

Further, as shown in FIG.
By contacting the side surfaces of the end seal member 19 with the side surfaces at both ends in the longitudinal direction of the elastic blade 7, leakage of toner from the side ends of the elastic blade 7 is prevented.

As shown in FIG. 3, the elastic blade 7 has a contact nip portion 7a with the developing sleeve 5 indicated by a hatched portion in the figure.
From the normal developing area to both ends of the elastic blade 5, and the positions of the ends 7 b of the elastic blade 7 at the both ends are determined by the above-mentioned contact. It is configured to be inside the nip 7a. In other words, the thickness of the toner layer formed on the developing sleeve 5 is affected by the distance from the point upstream of the contact nip 7b in the rotation direction of the developing sleeve 5 to the leading end. It is conventionally known that the toner layer to be formed is thicker and the shorter the toner layer becomes, the thinner the toner layer becomes.

In the present embodiment, the distance is shortened in a region in contact with the peripheral surface of the developing sleeve 5 corresponding to the uncontacted portion of the elastic roller 6 as compared with this distance in the normal developing region. Has increased the regulatory power on toner. The developing sleeve 5 at both ends of the elastic blade 7
In order to more reliably perform the above regulation, the positions of the elastic blade tips 7b at both ends thereof are configured to be within the contact nip portions 7a.
Is an edge contact.

For example, a good charge amount of -60 to
−20 (μC / g), 0.4 to 1.0 as a good toner coating amount
It is set so that mg / cm ² can be obtained.

Next, FIG. 4 is an enlarged view of an end portion of the developing device shown in FIG. 4, the developing sleeve 5 is not shown in FIG.

In the present invention, an end lubricating layer 71 as a lubricating layer is provided in a region from the contact nip portion 7a contacting the developing sleeve 5 via the toner 8 on the surface of the elastic blade 7 to the distal end portion 7b of the elastic blade 7. Is provided.

In FIG. 4, the end lubricating layer 71 is indicated by hatching, and is a region extending from the contact nip 7a between the elastic blade 7 and the developing sleeve 5 to the tip 7b of the elastic blade 7, and It is provided in the non-development area in the longitudinal direction. The end lubrication layer 71 is made of a different material from the elastic blade 7 as the base material, and is adhered to the surface of the elastic blade 7.

In this embodiment, the end lubricating layer 71 is formed of a solvent-soluble fluororesin. As a solvent-soluble fluororesin, an ethyl acetate solution of a fluoroolefin-vinyl ether-vinyl ester copolymer (trade name "Zeffle PG2000", manufactured by Daikin Industries, Ltd.) is used, and both ends of the above-mentioned elastic blade 7 are dipped by a dipping method. 5 ~ 4 film thickness
An end lubrication layer 71 of 0 μm was provided.

In addition to the case where the above-mentioned end lubricating layer 71 is a fluoroolefin-vinyl ether-vinyl ester copolymer, and the case where alcohol-soluble nylon or copolymerized polyester is used, the actual image durability (5,000 sheets of A4 width paper passing)
FIG. 5 shows the results. As is evident from the results, fluoroolefin-vinyl ether-
Only when the vinyl ester copolymer was provided with a film thickness of 5 to 15 μm, it was confirmed that so-called “toner leakage” near the end of the elastic blade 7 hardly occurred. Note that, even when a fluoroolefin-vinyl ether copolymer or a fluoroolefin-vinyl ester copolymer was used as the end lubricating layer 71, an equivalent effect was confirmed as shown in FIG.

As described above, when the elastic blade 7 is configured as described above, the toner 53 does not get caught or fused in the nip near the end of the elastic blade 58, and the toner layers at both ends of the contact nip 7a are removed. Also, it is no longer formed in a stripe shape. In addition, it is possible to prevent the toner layer from being excessively thick at both longitudinal end portions of the developing sleeve 5 due to the thick toner layer formed at both end portions of the elastic blade 7.

As a result, at both ends in the longitudinal direction of the developing sleeve 5, the so-called “toner leakage” in which the toner 8 transfers to the photosensitive drum 1 as a fog at the time of development, or the toner 8 scatters or drops, is securely prevented. Along with
The formation of a thin toner layer on the developing sleeve 5 by the elastic blade 7 can be stably and favorably formed, and the electrostatic latent image on the photosensitive drum 1 can be favorably developed.

[0077]

As described above, according to the first aspect of the present invention, since the lubricating layer is provided from the contact nip portion to the distal end portion of the surface of the elastic regulating member, the lubricating layer is sandwiched between both longitudinal ends of the elastic regulating member. It is possible to prevent the toner from being fused to the surface of the elastic regulating member, to surely prevent the inside of the image forming apparatus from being significantly contaminated by the developer, and to reduce the toner thin layer on the developer carrier by the elastic regulating member. The formation can be performed stably and favorably.

According to the second aspect of the present invention, by using a fluororesin having excellent slipperiness as the lubricating layer on the surface of the elastic regulating member, the developer can be caught between the longitudinal ends of the elastic blade or the surface of the elastic regulating blade can be prevented. And effectively prevent the developer from significantly contaminating the inside of the image forming apparatus, and stably and favorably form a thin toner layer on the developing sleeve by the elastic blade. Can be formed.

According to the third aspect of the present invention, a developer is provided by using a solvent-soluble fluororesin having excellent slipperiness, excellent adhesion to an elastic blade, and excellent flexibility as a lubricating layer on the surface of the elastic regulating member. Is more effectively prevented from being caught between the longitudinal ends of the elastic blade and from being fused to the surface of the elastic blade, and reliably preventing the developer from significantly contaminating the inside of the image forming apparatus. A thin toner layer can be stably formed on the developing sleeve.

According to the fourth aspect of the present invention, the lubricating layer is provided in the non-development region in the longitudinal direction of the elastic blade surface, so that the elastic blade surface lubricating layer does not adversely affect the image in the developing region. The thin toner layer on the developing sleeve by the blade can be formed stably and satisfactorily.

According to the fifth aspect of the present invention, the distance from the lowest point in the rotation direction of the developer carrying member of the nip portion of the elastic regulating member in contact with the developer carrying member to the tip of the elastic regulating member is adjusted by the elastic regulating member. By continuously shortening in the side end direction in the vicinity of both ends in the longitudinal direction, and by forming at least the front end at the side end of the elastic regulating member so as to be in the contact nip portion,
Even if the inner sides in the longitudinal direction of both ends of the elastic regulating member tend to float, the width of the nip contact portion is small and the contact portion is slightly edge-contacting, so that toner leakage is prevented while forming a lubricating layer. As a result, a thin layer of non-magnetic toner can be satisfactorily formed on the developing carrier, and the electrostatic latent image on the photoconductor can be favorably developed.

According to a sixth aspect of the present invention, there is provided a cartridge having the developing device according to any one of the first to fifth aspects, wherein the cartridge is detachable from the image forming apparatus main body so that the developer can be removed. Prevents the elastic blade from being caught between the longitudinal ends and being fused to the surface of the elastic blade, reliably preventing the developer from significantly contaminating the inside of the image forming apparatus, and the toner on the developing sleeve by the elastic blade. A developing cartridge which can stably and satisfactorily form a thin layer and has excellent handleability is obtained.

According to the seventh aspect of the present invention, there is provided an electrophotographic photosensitive member, and at least one of the first and second aspects of the present invention is provided as a process means.
And the developing device according to any one of the above items (5) to (5), which is integrally formed into a cartridge and is detachably attached to the main body of the image forming apparatus. To reliably prevent the image forming apparatus from being significantly contaminated by the developer, and stably and satisfactorily form the thin toner layer on the developing sleeve by the elastic blade. A process cartridge excellent in handleability can be obtained.

According to the present invention, an electrophotographic photosensitive member on which an electrostatic latent image is formed and an electrostatic latent image formed on the electrophotographic photosensitive member are developed. Wherein the developer is prevented from being pinched between the longitudinal ends of the elastic blade or fused to the surface of the elastic blade, and the image forming apparatus is formed by the developer. It is possible to obtain an image forming apparatus excellent in user-friendly handling, which can reliably prevent the inside of the developing sleeve from being significantly contaminated and can stably and favorably form a thin toner layer on the developing sleeve by the elastic blade.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a schematic sectional view of the developing device according to the first embodiment of the present invention.

FIG. 3 is a view of the developing device of FIG. 2 as viewed from a photoconductor direction.

FIG. 4 is an enlarged view of the vicinity of an elastic blade end in FIG. 3 as viewed from a photoconductor direction.

FIG. 5 is a table showing the results of actual image durability.

FIG. 6 is a table showing the results of actual image durability.

FIG. 7 is a schematic sectional view of a conventional developing device.

FIG. 8 is a view of a conventional developing device as viewed from a photoconductor direction.

FIG. 9 is a view of another conventional developing device as viewed from a photoconductor direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 2 ... Charging device 3 ... Laser beam 4 ... Developing device 5 ... Developing sleeve (developer carrying member) 7 ... Elastic blade (elastic regulating member) 71 ... End lubrication layer 7a ... Contact nip portion 7b ... Tip Part 8: Toner (developer)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Naoki Fuui 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H071 BA13 DA08 DA15 EA10 2H077 AA02 AA33 AD02 AD06 AD13 AD17 CA11 FA13 FA22

Claims (8)

[Claims] A developer container for storing a developer; a rotatable developer carrier extending to an opening of the developer container; and an elasticity restricting member that abuts on the developer carrier via a developer. A member, a rotatable elastic roller provided in contact with an abutting portion of the elastic regulating member with the developer carrier, and a rotatable elastic roller provided in contact with the developer carrier in the rotational direction upstream of the developer carrier; and a longitudinal direction of the developer carrier. An end sealing member provided in a gap between both ends and an opening of the developing container, wherein a contact nip on the surface of the elastic regulating member, which comes into contact with a developer carrier via a developer, A developing device, wherein a lubricating layer is provided in a region extending from the portion to the tip of the elastic regulating member. 2. The developing device according to claim 1, wherein said lubricating layer is made of a fluororesin. 3. The developing device according to claim 2, wherein said fluororesin comprises a solvent-soluble fluororesin. 4. The developing device according to claim 1, wherein said lubricating layer is provided in a longitudinal non-developing region of said elastic regulating member. 5. The distance between the lowest point in the rotation direction of the developer carrying member and the tip of the elastic regulating member at the contact nip portion of the elastic regulating member with the developer carrying member is closer to both ends in the longitudinal direction of the elastic regulating member. 5. The method according to claim 1, wherein the end portion of the elastic regulating member is formed in such a manner as to be continuously shortened in an end direction, and at least a tip end portion at a side end portion of the elastic regulating member is located within the contact nip portion. Developing device. 6. A developing cartridge having the developing device according to claim 1, wherein the developing cartridge is detachable from a main body of the image forming apparatus. 7. An image forming apparatus according to claim 1, wherein the electrophotographic photosensitive member and at least the developing device according to any one of claims 1 to 5 as a process means are integrally formed as a cartridge and are detachably mountable to an image forming apparatus main body. Characteristic process cartridge. 8. An electrophotographic photosensitive member on which an electrostatic latent image is formed,
A developing device according to any one of claims 1 to 5, for developing an electrostatic latent image formed on the electrophotographic photoreceptor,
An image forming apparatus comprising: